1. Field of the Invention
The present invention relates to telecommunication systems, and in particular, to a system and method for tracking the movement of a wireless device.
2. Background of the Invention
The use of wireless devices is increasing at a rapid rate. A majority of the people living in large metropolitan areas use one or more wireless devices on a daily basis. These people communicate with each other or access information on the Internet using, among other devices, wireless telephones, interactive pagers, personal digital assistants, and handheld computers. As technology continues to improve, wireless devices will become more useful; at the same time, they will decrease in size and weight, making them more portable than ever. Consequently, consumers may carry their wireless devices wherever they go. For some people, their wireless device will become indispensable.
The widespread use of the wireless telephones in the United States has prompted the Federal Communications Commission (FCC) to promulgate new rules related to emergency call processing. The FCC""s wireless Enhanced 911 (E911) rules require certain Commercial Mobile Radio Services (CMRS) carriers to begin transmission of enhanced location and identity information in two phases. The first phase, started on Apr. 1, 1998, required wireless service providers to transmit a 911 caller""s number and section of the cell site from which the call is originated to a public safety answering point (PSAP). The second phase, starting on Oct. 31, 2001, requires all wireless service providers to locate two-thirds of all 911 callers within 125 meters of their physical locations. In other words, for all 911 calls received, a PSAP must be able to pinpoint 67% of the callers within 125 meters.
Under the FCC rules, wireless communication networks and wireless telephones (or any wireless devices that can be used to call 911), must provide both the identity and location of the caller to a 911 dispatcher. To provide a caller""s identity, the wireless device will furnish a device identification, e.g., a mobile identification number (MIN), indicating in most instances the telephone number of the device. To provide a caller""s location, the wireless communication networks and wireless devices will use a network-based location system or a handheld location system installed within the wireless devices, or a combination of the two systems. An example of a handheld location system is a Global Positioning System (GPS) receiver. U.S. Pat. No. 5,663,734, which is incorporated herein by reference, discloses a GPS receiver and a method for processing GPS signals.
The existing and contemplated E911 technologies have a number of limitations. For example, the existing technology does not provide continuous location information. Using the existing technology, a PSAP that receives an E911 call reporting an emergency situation knows only the initial location of the caller at the time the 911 call was made. As a result, once the caller and the wireless device is moved to a subsequent location substantially away from the initial location, the PSAP information is outdated, and may even be useless. For example, if an emergency response team is dispatched to the initial location, and the caller had been moved to the subsequent location that is miles away from the initial location, the emergency response team would not be able to respond to the emergency. This is especially true if the wireless device is located in a fast-moving vehicle traveling in a complex highway system. Thus, for example, the existing technology is inadequate to provide meaningful assistance to 911 callers under the following exemplary circumstances: (1) a kidnapped victim who is being transported in the trunk of a car; (2) a hijacked bus driver who is unable to speak due to duress from the hijackers; and (3) an out-of-towner who is being chased by criminals in an area having landmarks that are unfamiliar to the out-of-towner.
FIG. 1 is a schematic diagram showing prior art wireless communication network 10 having a plurality of cell sites within which wireless telephone 110 travels. Base stations 121, 131, and 141 are located within cell sites 120, 130, and 140, respectively. While base stations 121, 131, and 141 are stationary, wireless device 110 is mobile. When wireless device 110 establishes a 911 call with PSAP 150 via MSC (mobile service center) 160 while wireless device 110 is located within cell site 120, a location system of wireless communication network 10 generates initial location information pinpointing wireless device 110 to be at a first location within cell site 120. If wireless device 110 is subsequently moved, e.g., to a second location in cell site 130 or a third location in cell site 140 during the wireless communication session, the existing location system does not generate subsequent location information for PSAP 150. Therefore, PSAP 150 has only the initial location information that an emergency response team could use to assist the user of wireless device 110. However, if the user and wireless device 110 are at either the second location or the third location, each of which is miles away from the first location, then dispatching the emergency response team to the first location is of little use.
The present invention is a system and method for tracking the movement of a wireless device. The present invention comprises a location system that can generate location information pinpointing the wireless device""s location. In preferred embodiments of the present invention, the location information can comprise point coordinates. The location system can be a network-based component or it can be a handheld unit integrated in the wireless device. A network-based location system can generate the location information using a plurality of methods. In an exemplary embodiment of the present invention, the network-based location system can generate the location information using triangulation across cell sites. An example of a handheld location system is a GPS receiver that is in communication with a constellation of GPS satellites. In preferred embodiments, both network-based and handheld location systems can provide redundancy, reliability, and increased accuracy.
The present invention further comprises a location server that can receive and process the location information. The location server comprises a memory, as an integral or separate component, for storing data that includes, among other things, the location information and identity information of the wireless device. In preferred embodiments, the identity information comprises a unique identification number of the wireless device. For example, the mobile identification number (MIN) of a wireless telephone could be used as the identity information. For other wireless devices, each device""s serial number or other unique attributes may be used as the identity information.
An embodiment of the present invention can enable a called party, such as a PSAP, to track the movement of a wireless telephone during a wireless communication session. In other words, by using the present invention, the PSAP can know the location of the wireless device at all times during the wireless communication session. In another embodiment, the called party may be a private entity that can receive the location information of the wireless device to accomplish one or more of actions.
A method for using the present invention can comprise the following steps. First, a wireless communication session can be established between the wireless device and the called party. The communication session may be a POTS (plain old telephone system) call or a voice-over-Internet Protocol (VoIP) call. Second, the location system can generate and provide initial location information to the called party. Subsequent location information may be generated by the location system based on rules. The rules may comprise generating the location information continuously, at regular intervals, or based on other criteria. Third, the location information can be used to performed an action. The action may be, for example, tracking or otherwise observe the movement of the wireless device during the wireless communication session. In some embodiments, the method can further comprise the step of using the location information to perform another action after the wireless communication session is terminated.
Accordingly, it is an object of the present invention to enable the called party to track the movement of the wireless device during the wireless communication session.
It is another object of the present invention to enable the called party to perform one or more actions using the location information after the wireless communication session is terminated.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings, and the attached claims.